The web (i.e., World Wide Web) is increasingly being used by people to plan their travels. A person planning a trip has many web-based resources available including web page search engine services, image search engine services, photographic forums, travel-related web sites, online travel booking services, and so on. Web page search engine services, such as Google and Overture, provide for searching for information on web pages that may be of interest to users. After a user submits a search request (also referred to as a “query”) that includes search terms, the search engine service identifies web pages that may be related to those search terms. For example, a user planning a trip to Cairo, Egypt may enter the query “Cairo Egypt tourism.” To quickly identify related web pages, the search engine services may maintain a mapping of keywords to web pages. This mapping may be generated by “crawling” the web to identify the keywords of each web page. To crawl the web, a search engine service may use a list of base web pages to identify all web pages that are accessible through those base web pages. The keywords of any particular web page can be identified using various well-known information retrieval techniques, such as identifying the words of a headline, the words supplied in the metadata of the web page, the words that are highlighted, and so on. The search engine service may generate a relevance score to indicate how related the information of the web page may be to the search request. The search engine service then displays to the user links to those web pages in an order that is based on their relevance.
Several search engine services also provide for searching for images that are available on the Internet. These image search engines typically generate a mapping of keywords to images by crawling the web in much the same way as described above for mapping keywords to web pages. An image search engine service can identify keywords based on text of the web pages that contain the images. An image search engine may also gather keywords from metadata associated with images of web-based image forums, which are an increasingly popular mechanism for people to publish their photographs and other images. An image forum allows users to upload their photographs and requires the users to provide associated metadata such as title, camera setting, category, and description. The image forums typically allow reviewers to rate each of the uploaded images and thus have ratings on the quality of the images. Regardless of how the mappings are generated, an image search engine service inputs an image query and uses the mapping to find images that are related to the image query. An image search engine service may identify thousands of images that are related to an image query and presents thumbnails of the related images. To help a user view the images, an image search engine service may order the thumbnails based on relevance of the images to the image query. An image search engine service may also limit the number of images that are provided to a few hundred of the most relevant images so as not to overwhelm the viewer.
It can be very tedious for a person to plan a trip using the currently available web-based resources. For example, a person planning an automobile trip from Los Angeles, Calif. to Washington, D.C. would need to identify various routes, identify the locations (e.g., cities or counties) along the routes, identify sights associated with each location (e.g., Gateway Arch in St. Louis, Mo.), evaluate the routes and sights, and select a preferred route and sights to visit along that route. Although it may be easy for a person to identify various routes, it can be difficult to identify the sights that may be of interest along each route. If the person knows the name of a sight, the person can submit web page or image search requests. The person can then attempt to evaluate the search results to decide whether to visit that sight. If the person, however, does not know all the possible sights for a route, the person may need to consult various travel resources (e.g., books and visitor bureau web sites) that may describe the sights for the various locations along a route. Not only is the process tedious, the person may not even identify the most desirable sights or may overlook a desirable sight that is identified, because the quality of images and information available varies greatly from sight to sight and resource to resource.